Standard Deviation in Excel 2007

Standard Deviation in Excel: Overview

The standard deviation is represented by the lowercase sigma (σ) symbol. It shows how much dispersion, or variation, is in the data from the mean. The larger the standard deviation, the more spread out the data. Finding a standard deviation by hand is complicated and prone to errors.

A standard deviation tells you how spread out your data is from a central point.

Standard Deviation in Excel: Steps

Sample question: Find the standard deviation for the following data set: 22,55,37,46,67,37,95,76,99,28Step 1: Enter your data into Excel in single column. For this example, type your data into cells A1 through A10. Your entries must be in a single column without gaps.Step 2: Click a blank cell anywhere on the worksheet. Then type “STDEV(A1:A10),” — without quotation marks. A1:A10 is the location of your data. If you placed your data in another column, make sure you change the formula. For example, if your data is in cells C3 through C13, change the formula to read “STDDEV(C3:C13)”.Step 3: Press “Enter.” The standard deviation for this data set is 27.189867393734907.That’s it!

Tip: There is another way you can calculate a standard deviation in Excel. If you have the Data Analysis ToolPak installed, you could run “Descriptive Statistics,” which would calculate the standard deviation.Tip: You could also type “STDDEV(22,55,37,46,67,37,95,76,99,28)” into a blank cell and get the same result. But if you are planning to do any other calculations with your data, it’s best to input it in cells.Warning: STDDEV assumes you are working with samples. If your data represents the entire population, use STDEVP instead.

Notes for Mac Users:
For Standard Deviation for a Population use:
STDEV.P(A1:A10)
For Standard Deviation of a Sample use:
STDEV.S(A1:A10)